Also, if 1 melee attack is killing you then you're doing something very very wrong and somehow managed to break the game and not get any HP when leveling.
Weakness is your friend, reduces all non crit damage dealt by 50%. In case you are bad at math that's almost half! Conditions are the way you win and almost every melee auto attack applies them and melee do a lot more damage than ranged.
Melee is high risk high reward, if you dislike it a lot it may not be for you.
And in regards to doing dungeons, I'm 60 now and I've pugged every dungeon so far as soon as they are available and haven't had to bow out of one yet. All it takes is a bit of determination.
Also playing melee since bwe1 when mobs your own level could put a hurtin on you 1v1 probably helps.
Other than those reasons you don't go from alive to immediately dead.